JPH07107021A - Remote equipment control system - Google Patents

Abstract

PURPOSE:To independently provide the loop constitution of plural terminal equipments and to easily switch the plural terminal equipments by switching a latch relay to the terminal equipment or a loop part for fault diagnosis by loop constitution control signals. CONSTITUTION:A pulse detection part 2 detects the pulse signals of the loop constitution control signals constituted of at least more than two pulse signals supplied from an external controller 1 through communication channel side terminals L1 and L2. A pulse counting part 6 transmits driving operation signals to a latch relay part 7 when the predetermined number of the pulse signals arrive. The latch relay part 7 switches the terminal contact points of the latch relay 8 from A2 to B2 and from A1 to B1 by the driving operation signals and connects the loop part 9 to a communication channel system. Also, by cancellation operation signals from the pulse detection part 2, the terminal contact points are switched from B2 to A2 and from B1 to A1, the terminal equipment 10 is connected to the communication channel system and a state capable of normal communication is attained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a loop control system in which a remote switching device is configured in a loop to diagnose a failure of a communication line system, and a terminal when a plurality of terminal devices are connected to the same communication line. The present invention relates to a switching control system for vessels.

[0002]

2. Description of the Related Art In order to perform fault diagnosis of a communication line system according to the prior art, as shown in FIGS. 5 and 6, a change in supplied voltage is detected to activate a relay. That is, as shown in FIG. 5, the configuration for diagnosing the failure of the communication line is such that the external control device 1 and the communication line side terminals L1, L
2, the voltage detection unit 20, the latch relay unit 24, the latch relay 25, the loop unit 26, the terminal side terminals I1, I
2 and a terminal device 27.

The external control device 1 corresponds to a center side connected via a communication line, for example, an exchange side, that is, a station side in the case of a public network communication line, and a communication line to the terminal device 27 side. It has a function of sending out a control signal of a DC voltage, for example, a loop configuration control signal consisting of a positive voltage + V and a negative voltage -V, via a communication line side terminal L1, L2 corresponding to a branch point. There is.

The communication line side terminals L1 and L2 are terminals used for the branch point of responsibility between the center side and the terminal device 27 side, which are connected via the communication line, and their return diagnostics. The side terminal L1 is connected to the other input side of the voltage detection unit 20 and the common terminal C1 of the latch relay 25,
The communication line side terminal L2 is connected to one input side of the voltage detection unit 20 and the common terminal C2 of the latch relay 25.

The voltage detecting section 20 includes a communication line side terminal L1,
The loop configuration control signal supplied via L2 is detected, and the drive operation signal and the drive release signal are sent to the latch relay section 24. This voltage detection unit 20 is
It is composed of one input side and one output side, one input side is connected to the communication line side terminal L2, the other input side is connected to the communication line side terminal L1, and the output side is a latch relay. It is connected to the input side of the section 24.

Here, the loop configuration control signal 21 is as shown in FIG.
As shown in FIG.
3 and 3. The loop configuration signal 22 has a predetermined time width T1 and a predetermined plus voltage + V with respect to the reference voltage value (zero volt in FIG. 6) of the DC voltage applied to the communication line. .
Further, the loop release signal 23, like the loop configuration signal 22, is based on the time width T1 (in the embodiment) with respect to the reference voltage value (zero volt in FIG. 6) of the DC voltage applied to the communication line. Has a longer predetermined time width T1 ′ and a predetermined negative voltage −V smaller than the positive voltage + V value.

The latch relay section 24 switches the contacts of the latch relay 25 based on the drive operation signal and the release operation signal from the voltage detection section 20, the input side of which is the output side of the voltage detection section 20. The output side is connected to the latch relay 25.

The latch relay 25 is composed of first and second latch relays 25A and 25B, which are connected to the communication line side terminals L1 and L2, respectively.

First and second latch relays 25A and 25B
Are the common terminals C1 and C2 and the contacts A1, A2 and B1,
B2, the common terminals C1 and C2 are connected to the communication line side terminals L1 and L2, the contact terminals A1 and A2 are connected to the output side of the latch relay section 24, and the contact terminals B1 and B2.
Are connected to the loop section 26.

The loop portion 26 has a predetermined impedance or the like for performing fault diagnosis, and is connected to the contact terminals B1 and B2 of the latch relay 25.

The terminal-side terminals I1 and I2 are terminals provided as branch points for separating the communication line-side terminals L1 and L2, and connect the terminal 27 and the communication line-side terminals L1 and L2 via the latch relay 25. To do.

The terminal device 27 is a device that performs various operations by communication, and is connected to the terminal-side terminals I1 and I2.

In the remote equipment control system having such a connection state, the loop control signal 22 (plus voltage + plus voltage) among the loop control signals 21 shown in FIG.
When V) is output, the positive voltage + V is applied to the voltage detection unit 20 via the communication line side terminals L1 and L2.

When the voltage detecting section 20 receives the plus voltage + V, it determines that it is the loop configuration signal 22, and sends a drive operation signal to the latch relay section 24 after a lapse of a certain time. In the latch relay unit 24, when the drive operation signal is received from the voltage detection unit 20, the contact terminals A1 and A connected to the common terminals C1 and C2 of the first and second latch relays 25A and 25B.
Switch from 2 to B1 and B2.

In this way, the terminal device 27 and the external control device 1 are separated from each other by the latch relay 25, and at the same time, the external control device 1 passes through the latch relay 25 and the loop portion 26.
And a loop configuration with a communication line system can be realized.

Further, when releasing the loop configuration with the communication line system, the voltage detecting section 20 loops by sending the loop release signal 23 (minus voltage -V) of the loop configuration control signal 21 shown in FIG. When it is determined that the configuration is released, the release operation signal is sent to the latch relay section 24. Then, the latch relay unit 24 can switch the connection state of the common terminals C1 and C2 of the latch relay 25 to the contact terminal A1 and A2 side to return to the normal communication enabled state.

[0017]

However, in the above-described conventional remote equipment control method, when a plurality of terminals having different main functions are connected to the same communication line, the terminals cannot be discriminated. There was a problem that each unique loop configuration could not be done.

Therefore, it is possible to independently realize a loop configuration in the case where a plurality of terminal devices having different main functions are connected to the same line, and to easily switch a plurality of terminal devices. It has problems that must be solved.

[0019]

In order to solve the above problems, a remote device control system according to the present invention is a remote device control system composed of an external control device and a terminal device connected via a communication line. Therefore, a latch relay is provided in the communication line, and this latch relay is switched to a terminal unit or a loop section for fault diagnosis by a loop configuration control signal composed of at least two or more pulse signals from an external control device. That is what I did.

Further, the remote device control method is one in which two or more pulse signals are counted by a counter, and when the count is a predetermined number of pulses, the loop signal is switched to a fault diagnosis loop section.

Further, the remote device control system of the present invention is a remote device control system composed of an external control device and a plurality of terminals connected through a communication line, and a latch relay is provided in the communication line. This latch relay is configured to switch to any one of a plurality of terminals according to a control signal composed of at least two pulse signals from an external control device.

The two or more pulse signals are counted by a counter, and based on the counted number of pulses, the remote device control system is switched to the terminal corresponding to the preset number of pulses.

[0023]

With the above structure, the following operation is achieved. (1). A latch relay is installed in the communication line, and this latch relay is switched to a terminal unit or a loop section for fault diagnosis by a loop configuration control signal from an external control device, so that the terminal unit can be appropriately operated by an external operation. Up to now, the condition of the communication line etc. will be diagnosed.

(2). Since the loop configuration control signal is composed of at least two or more pulse signals, switching of the loop configuration and normal communication can be easily realized simply by the number of pulses.

(3). Two or more pulse signals are counted by the counter, and when the count is a predetermined number of pulses, the loop portion for fault diagnosis is switched to thereby switch the communication line used for fault diagnosis. It becomes possible to avoid malfunction.

(4). A latch relay is provided in the communication line, and this latch relay is switched to any one of a plurality of terminals according to a control signal from an external control device. For example, a plurality of terminal devices having different main functions can communicate with each other. Even if it is connected on the line, it is possible to easily connect to the required terminal equipment by remote control.

(5). Since the control signal is composed of at least two or more pulse signals, switching of a plurality of terminal devices is performed by the number of pulse signals.

(6). Two or more pulse signals are counted by the counter, and based on the counted number of pulses, the terminal device corresponding to the preset number of pulses is switched to eliminate malfunctions and to ensure the necessity. It becomes possible to connect with terminal equipment.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a remote device control system according to the present invention will be described in detail below with reference to the drawings. For ease of understanding, the same parts as those of the conventional art will be described with the same reference numerals.

In order to diagnose the failure of the communication line system according to the present invention, as shown in FIGS. 1 and 2, the number of supplied pulse signals is detected and the relay is operated to form a loop. Has become. That is, in the first embodiment of the remote device control system for diagnosing a failure of a communication line, as shown in FIG. 1, an external control device 1, communication line side terminals L1 and L2,
The pulse detection unit 2, the pulse counting unit 6, the latch relay unit 7, the latch relay 8, the loop unit 9, the terminal-side terminals I1 and I2, and the terminal device 10 are included.

The external control device 1 corresponds to a center side connected via a communication line and sends a pulse signal to the terminal device 10 side by superimposing it on the DC voltage supplied on the communication line. It has a function and is connected to the communication line side terminals L1 and L2 corresponding to branch points.

The communication line side terminal L1 is connected to the other input side of the pulse detecting section 2 and the common terminal C1 of the latch relay 8, and the communication line side terminal L2 is one input side of the pulse counting section 6 and the latch relay. 8 common terminals C2.

The pulse detection unit 2 includes the communication line side terminals L1,
Among the pulse signals supplied via L2, it is converted into a pulse signal of a required voltage level, the pulse signal of the loop configuration control signal is detected, and the latch relay 8 is configured to perform a loop configuration or a loop release operation. . This pulse detection unit 2 is composed of two input sides and one output side, one input side is connected to the communication line side terminal L2, and the other input side is connected to the communication line side terminal L1. The output side is connected to the input side of the pulse counting unit 6.

Here, the loop configuration control signal 3 is composed of a loop configuration signal 4 and a loop release signal 5, as shown in FIG. The loop configuration signal 4 is different from the loop configuration signal 4 having a predetermined time width T1 and a predetermined plus voltage + V as in the prior art. That is, the loop constituent signal 4 is a plurality of rectangular waves composed of a plus voltage + V having a predetermined time zone T2 with respect to a reference voltage value (zero volt in the figure) of the DC voltage applied to the communication line, that is, a plurality of rectangular waves. It is composed of pulse signals 4a and 4b. The time zone T2 of the pulse signals 4a and 4b is set sufficiently shorter than the time zone T1 of the loop constituent signal 4A in the conventional technique shown in FIG. Further, the loop release signal 5 is similar to the conventional technique shown in FIG. 4 with respect to the reference voltage value (zero volt in the figure) of the DC voltage applied to the communication line
It is constituted by a predetermined time zone T1 'and is constituted by a minus voltage + V which is smaller than the plus voltage + V amount.

The pulse counting section 6 sends a driving operation signal to the latch relay section 7 when a predetermined number of pulse signals arrives. That is, the number of pulses of the loop constituent signal 4 of the loop constituent control signal 3 is detected. In the embodiment, two pulse signals 4a and 4b are used.
When the signal is detected, a drive operation signal is sent to the latch relay section 7. Further, the predetermined time period T1 ′ detected by the pulse detection unit 2
When the negative voltage is −V, the loop release signal is determined to be released and a loop release signal is sent to the latch relay section 7. The input side of the pulse counting section 6 is connected to the pulse detecting section 2, and the output side thereof is connected to the latch relay section 7.

The latch relay section 7 includes a pulse counting section 6
The contact of the latch relay 8 is switched by the drive operation signal from the pulse detector 2 and the release operation signal from the pulse detector 2. The + input is connected to the pulse counting unit 6 and the − input is pulse detected on the input side. The output side is connected to the latch relay 8.

The latch relay 8 is composed of first and second latch relays 8A and 8B as in the prior art, and each is connected to the communication line side terminals L1 and L2.

The first and second latch relays 8A and 8B
Are the common terminals C1 and C2 and the contact A as in the prior art.
1, A2 and B1, B2, and a common terminal C
1, C2 are connected to the communication line side terminals L1, L2, the contact terminals A1, A2 are connected to the output side of the latch relay section 7, and the contact terminals B1, B2 are connected to the loop section 9.

The loop section 9 has a predetermined impedance for fault diagnosis as in the prior art, and is connected to the contact terminals B1 and B2 of the latch relay 8.

The terminal-side terminals I1 and I2 are terminals provided to arbitrarily switch between the communication line-side terminals L1 and L2 as in the prior art, and the terminals 10 and the communication line-side terminals are connected via the latch relay 8. L1 and L2 are connected.

In the remote equipment control system having such a connection state, when the loop control signal 4 (plus voltage + V) of the loop control signal 3 shown in FIG. It is applied to the pulse detection unit 2 via the line side terminals L1 and L2.

The pulse detecting section 2 converts the pulse signal into a pulse signal having a required voltage level and outputs the pulse signal to the pulse counting section 6. In the pulse counting section 6, a predetermined pulse signal 4a,
When the number of 4b (two in the embodiment) arrives, a drive operation signal is sent to the latch relay unit 7, and the latch relay unit 7 switches the terminal contact of the latch relay 8 from A2 to B2, A1 to B1, and the loop unit. 9 is connected to the communication line system. As a result, a loop structure of the communication line system can be realized.

When the loop configuration of the communication line system is to be released, the pulse detection section 2 is released by supplying the negative voltage -V which is the loop release signal 5 of the loop configuration control signal 3 shown in FIG. Send the signal to the latch relay section 7,
The terminal contacts of the latch relay 8 are B2 to A2 and B1 to A
It is possible to switch to 1 and return to the normal communicable state.

Next, a second embodiment of the remote device control system according to the present invention will be described. As in the first embodiment, the same parts as those in the prior art and the first embodiment are designated by the same reference numerals for ease of understanding.

The remote device control system according to the second embodiment is
As shown in FIGS. 3 and 4, for a plurality of terminal devices,
The connection with the communication line system is switched by a control signal peculiar to each.

That is, in the second embodiment of the remote equipment control system for switching the communication lines, as shown in FIG. 3, the external control device 1, the communication line side terminals L1 and L2, and the pulse detecting section 2 are provided. , Pulse count A section 13 and pulse count B
Unit 14, pulse number determination unit 15, and latch relay unit 16
, A latch relay 17, terminal-side terminals I1 and I2, and terminals (first terminal 18 and second terminal 19).

The external control device 1 corresponds to the center side connected through the communication line and has a function of sending a pulse signal to the terminal side by superimposing it on the DC voltage supplied on the communication line. It is provided and is connected to the communication line side terminals L1 and L2 corresponding to branch points.

The communication line side terminal L1 is connected to the other input side of the pulse detecting section 2 and the common terminal C1 of the latch relay 17, and the communication line side terminal L2 is one input side of the pulse detecting section 2 and the latch relay. It is connected to 17 common terminals C2.

The pulse detection unit 2 includes the communication line side terminals L1,
The pulse signal supplied via L2 is converted into a pulse signal of a required voltage level, the pulse signal of the control signal is detected, and the latch relay 17 is switched. The pulse detection unit 2 is composed of two input sides and one output side, one input side of which is a communication line side terminal L.
2, the other input side is connected to the communication line side terminal L1, and its output side is connected to the respective input sides of the pulse count A section 13 and the pulse count B section 14.

Here, the control signals 11 and 12 are, as shown in FIG. 4, a plurality of rectangular waves of plus voltage + V having a predetermined time zone, as in the first embodiment described above.
That is, it is composed of a plurality of pulse signals. In the present embodiment, as shown in FIG. 4A, two pulse signals 1
In the case of 1a and 11b, the first terminal 18 is shown in FIG.
, The three pulse signals 12a, 12b, 12
In the case of c, it switches to the second terminal device 19.

When the control signal 11 for switching to the first terminal unit 18 arrives, the pulse count A section 13 outputs "HIGH".
The H "signal is output to the pulse number determination unit 15, the input side thereof is connected to the pulse detection unit 2, and the output side thereof is connected to the pulse number determination unit 15.

When the control signal 12 for switching to the second terminal device 19 arrives, the pulse count B unit 14 "HIG".
The H "signal is output to the pulse number determining unit 15, the input side of which is connected to the pulse detecting unit 2 and the output side of which is connected to the pulse number determining unit 15. The pulse count A The section 13 and the pulse count B section 14 are not limited to this, and have a structure that can be increased according to the number of the terminals 10A, 10B, ... Connected to the communication line.

The pulse number judging section 15 is composed of the terminals 10A, 1
0B, ... corresponding to the number of input terminals and output terminals A,
., And in the case of the present embodiment, "H" from the pulse count A section 13 and the pulse count B section 14
It has a so-called multiplexer function of making either of the output terminals A and B a "HIGH" signal in response to the "IGH" signal. It is connected to the count A section 13 and the pulse count B section 14, and its output terminals A, B ... Are connected to the latch relay section 16.

The latch relay section 16 includes a pulse number determination section 1
5, which controls the latch relay 17 in response to the "HIGH" signal input from the terminal 5, and has a configuration including input terminals corresponding to the number of output terminals A, B, ... Has become. In this embodiment, the control signals 11 and 12 from the pulse count A section 13 and the pulse count B section 14 are received. For example, if the signal is the pulse count A section 13, the latch relay 17 is switched to the A side. If the control signal 12 is from the pulse count B unit 14, the latch relay 17 is switched to the B side.
The input side of the latch relay unit 16 is connected to the pulse number determination unit 1
5 is connected to the output terminals A and B, and the output side thereof is connected to the common terminals C1 and C2 of the latch relay 17.

The latch relay 17 includes the first and second latch relays 17A and 17B as in the prior art and the first embodiment.
And are respectively connected to the communication line side terminals L1 and L2.

The first and second latch relays 17A, 1
7B is composed of common terminals C1 and C2 and contacts A1, A2 and B1 and B2 as in the prior art and the first embodiment, and the common terminals C1 and C2 are communication line side terminals L1 and L.
2, the contact terminal A1 is connected to the terminal side terminal I1,
The contact terminal A2 is connected to the terminal terminal side I2, and the contact terminal B1
Is connected to the terminal side terminal I1 ', and the contact terminal B2 is connected to the terminal side terminal I2'.

The terminal-side terminals I1 and I2 are terminals provided for switching based on the control signal 11, and connect the first terminal 18 and the communication line-side terminals L1 and L2 via the latch relay 17. To do.

The terminal terminals I1 'and I2' are connected to the control signal 1
2 is a terminal that can be switched on the basis of the second terminal device 19 and the communication line side terminal L1 via the latch relay 17.
Connect with L2.

The terminal devices 18, 19, ... Are composed of a plurality of terminals, and have control signals 11, 12,
Is connected to the communication line by ...
In the embodiment, the first terminal 18 and the second terminal 1
It is composed of nine. Further, the plurality of terminals connected to the communication line may be terminals having different functions, terminals having the same functions, or terminals having a loop mechanism for fault diagnosis of a predetermined terminal. It has a good structure.

For example, as a first specific example, the first terminal 18 is a terminal having a normal communication function, and the second terminal 19 is provided for diagnosing the failure of the first terminal 18, so to speak. It may be a terminal device.

As a second specific example, the first and second terminals 18 and 19 are terminals having a communication function having the same or different functions, and separately described in the first embodiment for fault diagnosis. The loop configuration may or may not be provided.

In the remote device control system according to the second embodiment having such a connection state, first, when the external control device 1 outputs the control signal 11 including the two pulse signals 11a and 11b shown in FIG. Communication line side terminals L1, L
It is applied to the pulse detection unit 2 via 2.

The pulse detecting section 2 converts the pulse signal into a pulse signal having a required voltage level and outputs it to the pulse count A section 13 and the pulse count B section 14. Pulse count A section 1
In 3, when the two pulse signals are counted, "HIG
The signal of "H" is output, and the pulse count B part is "LOW".
The signal of is output. This is input to the pulse number determination unit 15.

In the pulse number judging section 15, the "HIGH" signal of the pulse count A section 13 and the pulse count B section 1
From the "LOW" signal of 4, the output of the output terminal A side of the pulse number determination section 15 becomes a "HIGH" signal, and the latch relay section 16 connects the contacts of the latch relay 17 to the A1 and A2 sides, Is connected to the communication line system.

Further, when the control signal 12 consisting of the three pulse signals 12a, 12b, 12c shown in FIG. 4 is output from the external control device 1, the pulse detecting section 2 is transmitted via the communication line side terminals L1, L2. Applied to. The pulse detection unit 2 converts the pulse signal into a pulse signal having a required voltage level and outputs the pulse signal to the pulse count A unit 13 and the pulse count B unit 14.

The pulse count B section 14 outputs a "HIGH" signal when three pulse signals are counted, and the pulse count A section 13 outputs a "LOW" signal.
In the pulse number determination unit 15, “H” of the pulse count B unit 14
IGH "signal and pulse count A section" LOW "
From the signal of, the output terminal B side of the pulse number determination unit 15 is "H".
IGH "signal, the latch relay section 16 switches the contacts of the latch relay 17 to the B1 and B2 sides, and the second terminal 19 is connected to the communication line system. In this way, the control signal 11 is sent to the communication line. , 12 are superposed and the terminal device 18,
It is possible to switch 19 times.

[0067]

The remote device control system according to the present invention has the following effects by having the configuration described above. (1). A latch relay is installed in the communication line, and this latch relay is switched to the terminal unit or the loop section for fault diagnosis by the loop configuration control signal from the external control device. It is possible to easily diagnose the state of the communication line, and to bring about an extremely excellent effect that the labor cost can be saved and the trouble can be dealt with quickly.

(2). Since the loop configuration control signal is composed of at least two pulse signals, it has an extremely excellent effect that the line can be easily switched for fault diagnosis.

(3). Two or more pulse signals are counted by a counter, and when this count is a predetermined number of pulses,
By switching to the loop section for fault diagnosis, it is possible to avoid malfunction of switching of the communication line used for fault diagnosis, and it is possible to perform fault diagnosis while maintaining the reliability of the communication line. It has an extremely excellent effect.

(4). By arranging a latch relay in the communication line and switching this latch relay to any of a plurality of terminal units according to a control signal from an external control device, a plurality of terminal devices having different main functions can perform the same communication operation. Even if it is connected on the line, it has an extremely excellent effect that it can be easily connected to a required terminal device.

(5). Since the control signal is composed of at least two or more pulse signals, there is an extremely excellent effect that the control by the pulse signal can be easily performed.

(6). Two or more pulse signals are counted by a counter, and the number of counted pulses is switched to a terminal device corresponding to a preset number of pulses, so that a malfunction is eliminated and a terminal device is surely needed. With this, it is possible to switch the connection while maintaining the performance of the communication line, which is an extremely excellent effect.

[Brief description of drawings]

FIG. 1 is a circuit diagram showing a schematic connection state of a remote device control system according to a first embodiment of the present invention.

FIG. 2 is a schematic waveform diagram of the loop configuration control signal.

FIG. 3 is a circuit diagram showing a schematic connection state of a remote device control system according to a second embodiment of the present invention.

FIG. 4 is a schematic waveform diagram of the same loop configuration control signal.

FIG. 5 is a circuit diagram showing a schematic connection state of a remote device control system according to a conventional technique.

FIG. 6 is a schematic waveform diagram of the loop configuration control signal.

[Description of Codes] 1 External control device 2 Pulse detection unit 3 Loop configuration control signal 4 Loop configuration signal 5 Loop release signal 6 Pulse counting unit 7 Latch relay unit 8 Latch relay 8A First latch relay 8B Second latch relay 9 Loop unit 10 Terminal device 11, 12 Control signal 11a, 11b, 12a, 12b, 12c Pulse signal 13 Pulse count A unit 14 Pulse count B unit 15 Pulse number determination unit 16 Latch relay unit 17 Latch relay 17A First latch relay 17B Second latch relay 18 First terminal 19 Second terminal

Claims (4)

[Claims] 1. A remote device control system comprising an external control device and a terminal device connected via a communication line, wherein a latch relay is provided in the communication line, and the latch relay is provided from the external control device. The remote device control system is characterized by switching to the terminal unit or a loop unit for fault diagnosis by a loop configuration control signal composed of at least two pulse signals. 2. The two or more pulse signals are counted by a counter, and when the count is a predetermined number of pulses,
The remote device control method according to claim 1, wherein the loop unit is used for fault diagnosis. 3. A remote equipment control system comprising an external control device connected via a communication line and a plurality of terminals, wherein a latch relay is provided in the communication line, and the latch relay is the external control device. A remote device control system characterized in that a control signal composed of at least two or more pulse signals from the device is switched to any one of the plurality of terminals. 4. The above-mentioned two or more pulse signals are counted by a counter, and based on the counted number of pulses, the terminal device corresponding to the preset number of pulses is switched to. Item 3. A remote device control method according to item 3.